Method and apparatus for preparing dental prosthesis



1951 J. J. JABLONSKI ETAL 2,577,420

METHOD AND APPARATUS FOR PREPARING DENTAL PROSTHESIS Filed Dec. 15, 1949A A 2 SHEETS--SHEET 1 INVENTORS Charlesl Hummer BYz f fi ATTORNEY dse hJJabZanskz' 2 SHEETS-SHEET 2 J. J. JABLONSKI ET AL METHOD AND APPARATUSFOR PREPARING DENTAL PROSTHESIS Filed Dec.

Dec. 4, 1951 INVENTORS 7' Joseph J. 'clzbla'nsltz Clza H 5 Patented Dec.4, 1951 METHOD AND APPARATUS PREPARING DENTAL PROSTH-E S'IS Joseph J..Jablonski and Charles I. Hummer, Detroit, Mich.

Application December 13, 1949, Serial No. 132,746

While the apparatus and method of use has been described more or less indetail, "itfils ob vious that changes-in the apparatus and method may bemade without departing from the scope of the following claims definingour invention; This invention relates to the apparatus and method forpreparing full or partial dentures which can be accurately reproducedand accurately conform to mouth conditions existing prior to anyextractions.

At the present time practically all dentures are prepared by takingcasts and measurements subsequent to extraction and relying ratherheavily on the patients feeling of comfort.

Such reliance can not be trusted due to the fact I that a considerabletime usually elapses between extraction and completion of the dentures.In cases where dentures are lost or crushed the patient has togo'through'the more or'less-standard procedure of taking mensurementsand casts and it becomes almost impossible to produce-a comfortable andwell fitted denture which will be most favorable to the 'patient'sappearance.

The hard palate area, and particularly :the frontal portion thereof,being backed up by relatively thick and immovable skull bones:positioned some distance from the tooth supporting area, is not subjectto any substantial change in the adult person .and is undoubtedly the:most suitable portion of the entire buccallcavity. The hard palate areawith its rigid frontal arch is to the .buccal :cavity what finger printsare to the body and provided proper measurements are made, the truenormal and natural arch :and

articulation can be accurately reproduced. It I is an object, therefore,of the present invention to provide apparatus and a methodfor1accurately producing dentures conforming to the natural shape mostfavorable to the patient.

A further object of .the invention is :the :provision of apparatus and amethod wherebydup'licate dentures :can be readily produced without anyinconvenience to the patient.

'Avstill further :object .ofthe invention is the provision of apparatusand a methodwhereby dentures can be produced in accordance withmeasurements and casts made long prior to any extractions whereby thetrue normal and natural dental arch and articulation can :bexreproducedwhenever desired.

These and other objects of the invention will be apparent to personsskilled in the art from a study of the following description and:accompanying drawings, :in'which 1, is an elevational view oi'theimproved 9 Olaims. (CI. 32-32) iii 2 apparatus located in a more .orless standard form of articulator;

"Fig. 2 :is :a plan view of the improved lower matrix former and indexmember;

Fig-3 is a sectional view taken substantially on &1ine 3. '3 of Fig. 2;

Fig. 4 is a sectional view through the improved lower .matrix former andshowing the former filled with soft plaster;

Fig. 55 is a sectional view similar to Fig. 4 but showing the indexmember or locator pushed into the softiplaster;

Fig. 6 is a sectional view similar to Fig. 5 "but showing a subsequentstep in which the cast of vthe Iupper natural'teeth :is pushed :into thesoft plaster to the properposition;

Fig. '7 isa sectional view similar to Fig. .6 but showing a .still laterstep in the method and in whichathe cavity in the upper cast has beenfilled to :form the palatal index cast;

Fig. 8 is a sectional view showing thematrix removed from the former;

Fig.9 is an elevationalvi'ew and :Fig. 10 a plan view of the :palatalidentification vcast iproduced asshown in Fig.7.;

'11 :is :a sectional view showing the upper cast mounted in its trueposition on the palatal identification cast and the lower. matrix;

Fig. l2zis an isometric view of the index memberror lo'cator, and

Fig. .1 3 is ea plan 'view of the articulator of Referring now to thedrawings in detail it "will be :seen from Figs. 1 and 13 that a :moreorless standard form of articulator is used for illustrathteipurposes, butitis to be understood that other types of articulators can also be usedwhile :still using the same apparatus and method laterto be described.As shown in Figs. l and 13 the articulator is formed with a base 12 fromwhich a pair of posts 4 extend upwardly to the adiusta-ble 'condylerod-joint 6. From the condyle red the upper jaw member 8 extends"forward-1y land has mounted therein th-eiincisal pin it adjnstablycarried by the "upper jaw for clamping in any desired position by thumbscrew .H. The lower end of the incisal .pin bears upon the incisal guide12 which may be adjusted :in various angular positions and heights. Thebase 2 :and arm -8 are provided with positioning plates 14 slotted as at[-5 and having :a central opening therein through which an ejectingscrew may more under operation by thumb screws [6 threaded into the'baseand upper .arm.

Upper and lower .imatrix formers t8 Ian'dIZ'U respectively are providedand each of the formers is formed with a substantially circular baseportion 22 counterbored as at 24 so as to closely fit over thepositioning plates M. A pin 26 is fastened in each base and adapted toengage in the slot I so as to correctly and accurately locate the matrixformer on either the articulator base 2 or arm 8. Extending upwardlyfrom the base portion of the matrix formers are outwardly sloping walls28 inclined at such an angle as to permit ready dischange of the plastercast to assist in removal of the plaster cast. An ejecting screw 30 isthreaded into the bottom portion of the cup-like matrix former and thisscrew is centrally located with respect to the screw [6 so that theentire matrix former can be readily removed from the articulator bypressure applied centrally thereof. One wall of the cup-like matrixformer is provided with a flange 32 having a slot 33 formed therein anda hole is drilled or otherwise formed in the flange to receive a pin'34preferably located centrally in the slot 33. This pin 34 is adapted toextend through a hole in an arm 36 extending outwardly from a truncatedpyramidal projection 38, all as clearly shown in Figs. 2, 5, 6 and 12.The truncated pyramidal projection 38 is adapted to project into the cupshaped matrix former to provide an exact locating position for a cavityin the plaster cast in the former. For ready removal of the cavitylocator or index member a projection 49 extends from the arm 36 in adirection opposite to the truncated pyramidal projection 38. From thepreceding it will be seen that a new and improved apparatus has beendevised for use with one type of articulator. It will be obvious that byslight changes, either in the base portion 22 of the matrix formers orby attaching standard 10- eating plates l4, the apparatus can be usedwith other types of articulators.

In using the apparatus just described it is preferable that thenecessary facial readings for condyle and incisal guide settings betaken and recorded in any known manner and an upper denture cast 59 madeof the natural teeth. All of this is preferably done prior to any toothextraction and at least prior to any general extraction. After the upperdenture cast 50 has been made it is mounted in an articulator with thecondyle and incisal guide settings made in accordance with thepreviously recorded readings. Following this the lower matrix former isplaced in the articulator and filled to the desired level with softplaster 52 as shown in Fig. 4. While the plaster is still soft the indexmember or locator 38 is forced into the plaster as shown in Fig. 5, thenthe upper denture cast is closed into the soft plaster so as to get thetooth impression therein, all as clearly shown in Fig. 1. After theplaster has hardened the upper denture cast is lifted or swung back tothe line and dash position of Fig. 1 and the index member or locatorremoved. The upper denture cast and lower matrix is then coated with aseparating fluid and the palatal cavity filled with dental stone 54 asshown in Fig. '7. As soon as this has hardened the upper denture castmay be removed and the'palatal cast 54 as shown in Figs. 9 and 10removed. All the parts may now be removed from the matrix formers andplaced in their matching positions as shown in Fig. 11 with all thenecessary readings for resetting the articulator recorded on the lowermatrix 52. Whenever. at some subsequent date it is desired to produce aset of teeth for the patient the parts may again be readily assembled inthe articulator and each part must assume its exact position. This isobvious since the tapering walls of the matrix former will definitelylocate the position of the matrix 52 therein and the truncated pyramidalprojection of the palatal cast 54 must fit into its exact position onthe lower matrix thus placing the true cast of the palate in its exactrelationship to the tooth impressions made in the lower matrix by theteeth of the natural denture cast 50. It will thus be seen that eventhough the gum lines change, requiring necessary changes in thedentures, the true location of the teeth can be reproduced at any timefrom the preserved record. It is believed unnecessary to go into thedetails of the denture manufaoture since any of the well known methods 7may be followed and regardless of the method followed a natural shapedand well fitted denture can be prepared since all readings and positionsoriginally taken can be exactly duplicated by use of the recordedreadings and the permanent casts illustrated in Fig. 11.

While the apparatus and method of use has been described more or less indetail, it is obvious that changes in the apparatus and method may bemade without departing from the scope of the following claims, definingour invention.

What is claimed is:

1. In a dental apparatus the combination of, an articulator adapted toreproduce movements and spacings of a patients jaws, a locator plateattached to the articulator, a lower matrix former engageable with saidlocator plate and adapted to receive plaster for casts, and a cavitylocator adapted to be mounted on said matrix former and projecting intothe same.

2. In a dental apparatus the combination of, an articulator adapted toreproduce movements and spacings of a patients jaws, a locator plateattached to the articulator, a lower matrix former engageable with saidlocator plate and adapted to receive plaster for casts, and a cavitylocator adapted to be mounted on said matrix former and projecting intothe same, said cavity locator having the projecting portion thereofformed as with a downwardly projecting inverted truncated pyramid.

3. In a dental apparatus the combination of, an articulator adapted tobe set to facial measurements of a patient, a matrix former carried bysaid articulator, and a cavity producing 10- cator mounted on saidmatrix former and projecting into the same.

4. In a dental apparatus the combination of, an articulator adapted tobe set to facial measurements of a patient, a matrix former carried bysaid articulator, a recess formed in the rim of said matrix former, anda cavity producing locator having a portion thereof positioned in saidrecess and an inwardly directed portion terminating in a downwardlydirected projection having tapered sides.

5. In a dental apparatus the combination of, an articulator adapted tobe set to facial measurements of a patient, a matrix former carried bysaid articulator, and a cavity producing 10-- cator having a slot andpin connection with said matrix former, and projecting into said matrixformer to form a cavity in a cast produced in said matrix former. 6. Themethod of producing dentures conformmouth comprising in part, securingthe pre-extraction facial measurements of the patient, making an upperdenture cast and mounting the same in an articulator in accordance withthe facial measurements, attaching a lower matrix former to thearticulator and substantially filling the same with plaster or otherhardenable material, pushing an index member into the hardenablematerial and closing the upper denture cast into the material, allowingthe material to harden then lifting the upper denture cast and removingthe index member, reclosing the denture cast onto the hardened materialand filling the palatal arch and cavity left by the index member with ahardenable material, and allowing this material to harden to produce anexact pattern of the patients palatal area whereby the exact naturalconfiguration of the patients mouth may be reproduced in conjunctionwith the facial measurements.

7. The method of producing dentures conforming to the naturalconfiguration of a patients mouth comprising in part, securing thefacial measurements of the patient, making an upper denture cast,placing said upper denture cast in an articulator set to the facialmeasurements, and filling in the palatal area of the upper denture castto produce a palatal index cast whereby the exact natural configurationof the patients mouth may be reproduced in conjunction with the facialmeasurements.

8. Dental apparatus comprising, a matrix former adapted to be mounted onan articulator set to facial measurements of a patient, and a cavityproducing locator mounted on said matrix former and projecting into thesame.

9. Dental apparatus comprising, a matrix former adapted to be mounted onan articulator set to facial measurements of a patient, a recess formedin said matrix former, and a cavity producing locator having a portionthereof positioned in said recess and an inwardly directed portionterminating in a downwardly directed projection having tapered sides.

JOSEPH J. JABLONSKI. CHARLES I. HUMMER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,457,385 Morison June 5, 19232,200,058 Chott May 7, 1940 2,234,411 McDonald Mar. 11, 1941 OTHERREFERENCES The Dental Cosmos, 1914, page 418.

